A medicine packaging apparatus, a medicine packaging sheet remaining amount determination method, and a medicine packaging sheet roll make it possible to accurately determine a remaining sheet amount of a medicine packaging sheet. The apparatus includes: a roll support section (2) to which a core tube (201) of a medicine packaging sheet roll (200) is attached； a sensor (24a) disposed in the roll support section (2) for an output of a count value in accordance with a rotation amount； a wireless reader-writer (26) which has antennas (25) in the roll support section (2) and writes information to a core tube IC tag (202) disposed in the core tube (201) and reads the written information, using the antennas (25)； an information generation section (57a) for generation of information to be written to the core tube IC tag (202)； a remaining sheet amount estimation section (57) for estimation of a current amount of remaining sheet based on the information and dimensional information of the core tube (201)； and a controller (5) which selectively performs an operation for a case where a reference time-point count value is not yet written to the core tube IC tag (202) and an operation for a case where the count value is already written thereto.
